Prepare the Rice and Ingredients: Wash the rice under cold water 2-3 times until the water runs clear. Drain well. Peel and julienne the ginger into thin matchsticks. Thinly slice the chicken and set aside.
Marinate the Chicken: In a bowl, combine the sliced chicken with oyster sauce, cornstarch, 2 tbsp chicken broth, oil, and salt. Mix well and let it marinate for 10-15 minutes while you start the congee. This step adds flavor and prevents the chicken from clumping.
Start the Congee Base: In a large pot, bring 6 cups of chicken broth (and 1 cup water if desired) to a rolling boil over high heat. Add the washed rice, ginger matchsticks, and ½-¾ tsp salt. Stir once to combine.
Simmer the Congee: Once boiling, reduce heat to medium-low and partially cover the pot. Simmer for 25-30 minutes, stirring occasionally to prevent sticking. The rice should start breaking down into a porridge-like consistency.
Whisk for Silkiness: After 25 minutes, use a whisk to vigorously stir the congee for 2-3 minutes. This breaks up the rice grains for that signature creamy texture—don't skip it!
Add the Chicken: Increase heat to medium-high. Gently add the marinated chicken slices, spreading them out. Stir for 1-2 minutes until the chicken is just cooked through (it will turn opaque). Avoid overcooking to keep it tender.
Finish and Adjust: Taste and add more salt, broth, or water if the congee is too thick. Simmer for another 5 minutes if needed. Remove from heat.
Serve: Ladle into bowls and garnish with sliced green onions. Drizzle with sesame oil for extra aroma. Enjoy hot!